Pyrotechnic composition

ABSTRACT

A pyrotechnic composition which contains powders of (1) aluminum, (2) metal oxide, and (3) a metal which is iron, copper, silver, niobium, tungsten, or molybdenum, and which also contains (4) a source of gas which is either (a) a gas maintained under a pressure of 1.05 to 10 atmospheres or (b) a fluorocarbon which vaporizes or decomposes when exposed to the heat of the alloying and oxidizing reaction to generate a gas.

United States Patent 1 Helms, Jr. et a1.

UNITED STATES PATENTS 3,565,706 2/1971 Waite 149/37 June 17, 19753,695,951 10/1972 Helms et a1 149/44 Primary Examiner-Stephen J.Lechert, Jr. Attorney. Agent, or Firm-R. S. Sciascia; J. A. Cooke [57]ABSTRACT A pyrotechnic composition which contains powders of (1)aluminum, (2) metal oxide, and (3) a metal which is iron, copper,silver, niobium, tungsten, or molybdenum, and which also contains (4) asource of gas which is either (a) a gas maintained under a pressure of1.05 to 10 atmospheres or (b) a fluorocarbon which vaporizes ordecomposes when exposed to the heat of the alloying and oxidizingreaction to generate a gas.

9 Claims, No Drawings PYROTECHNIC COMPOSITION CROSS-REFERENCE TO RELATEDAPPLICATION The present application is a continuation of copendingapplication, Ser. No. 227,632, filed Feb. 18, 1972, entitled pyrotechniccomposition, now abandoned.

BACKGROUND OF THE INVENTION This invention generally relates topyrotechnic compositions and more particularly to pyrotechniccompositions containing aluminum.

Pyrotechnic torches which use gaseous, liquid or solid fuel componentshave been developed for cutting or severing purposes. Most of thesetorches, however, transfer the energy obtained from the device by meansof a jet of hot gases. The heat generated from most existing torches,whether they be solid, liquid or gaseous, is usually the result ofreaction between a fuel component and an oxidizer and in most caseslarge quantities of oxidizer are required. The large quantity ofoxidizer needed in these compositions creates a very serious safetyproblem. Though these devices have found extensive use they are notalways dependable, efficient or economical.

Combined exothermic alloying and oxidizing reactions which result in theevolution of large quantities of heat have been applied in the past tothe pyrotechnic field as disclosed in US. Pat. No. 3,503,814, issuedMar. 31, 1970 to Horace H. Helms, .lr., and Alexander G. Rozner as wellas Ser. No. 49,980, file June 25, 1970 entitled Pyrotechnic composition"by Horace H. Helms, Jr., and Alexander G. Rozner, now US. Pat. No.3,695,951, issued Oct. 3, 1972. Although the materials disclosed thereinare suitable for use in many pyrotechnic applications there is a needfor improved materials in this area. For instance, there is a continuingneed for materials having a controlled high energy output. There is alsoa need to replace the nickel of the hereinbefore referenced patent andapplication with an element or elements that are not subject torestricted usage caused by periodic shortages. There is also a need forpyrotechnic materials that produce a low magnetic signature.

Therefore continued research has been directed toward development ofpyrotechnic compositions which overcome the above-mentionedshortcomings.

SUMMARY OF THE INVENTION Accordingly, one object of this invention is toprovide a pyrotechnic composition.

Another object of this invention is to provide a pyrotechnic compositionwhich is relatively safe to handle and store.

'Still another object of this invention is to provide a pyrotechniccomposition which is easy to process.

Another object of this invention is to provide a pyrotechnic compositionwhich uses readily available materials.

Yet another object of this invention is to provide a pyrotechniccomposition which reacts at a controlled rate to give off a largequantity of heat which is in a readily usable form.

Another object is to provide a pyrotechnic composition wherein energytransfer is accomplished by a hign velocity jet of molten materialrather than by gaseous ets.

A further object of this invention is to provide a pyrotechniccomposition which is dependable,'efficient and economical.

A still further object of this invention is to provide a pyrotechniccomposition which has a relatively low magnetic signature.

Yet another object of this invention is to provide a pyrotechniccomposition suitable for use in a cutting torch.

Still another object of this invention is to provide a pyrotechniccomposition which can be used as a heat producer.

Yet another object of this invention is to provide a pyrotechniccomposition which can be used as a light producer.

These and other object of this invention are accomplished by providing apyrotechnic composition comprising (1) aluminum, (2) metal oxide, (3) ametal selected from the group consisting of iron, copper, silver,niobium, molybdenum and v mixtures thereof which form a molten materialduring the alloying and oxidizing reaction and (4) a source of gas whichwhen exposed to the heat of the alloying and oxidizing reaction providesa gas which forces the molten material out of a container.

DESCRIPTION OF THE PREFERRED EMBODIMENT The pyrotechnic composition ofthis invention as hereinbefore noted contains a number of differentsubstituents.

The aluminum present in the instant composition should constitute from 5to 35 weight percent of the composition with a range of 20 to 30 weightpercent being preferred.

The metal oxide or mixture of metal oxides of this composition shouldconstitute 20 to weight percent of the total composition with a range of35 to 60 weight percent being preferred. The preferred metal oxides areFe O Fe O CuO, Cr O C0 0,, and mixtures thereof. It should be noted thatwithin the context of this invention the term metal oxide is intended tomean both one metal oxide and a mixture of more than one metal oxide.

The third component of this composition is a metal which constitutes lto 50 weight percent and preferably 5 to 30 weight percent of thecomposition. This metal is selected from the group consisting of iron,copper, silver, niobium, tungsten, molybdenum and mixtures thereof.

The fourth component is a source of gas. The term source of gas isintended to mean either one gas separately, a mixture of gases, a solidmaterial separately, a mixture of solid materials, a liquid materialseparately, a mixture of liquid materials, mixtures of one gas and oneliquid or several liquids, mixtures of several gases and one liquid orseveral liquids, mixtures of one gas and one solid or several solids,mixtures of several gases and one solid or several solids, as well asmixtures of one or several gases with one or several liquids and one orseveral solids. In other words source of gas is intended to include allcombinations of one or more gases, one or more liquids, one or moresolids and all mixtures thereof. With respect to the liquids and solidsthe liquids and solids included in the term source of gas are thosewhich will produce a gas either by vaporization or decomposition whenexposed to the heat of the alloying and oxidizing reaction.

When the source of gas is gaseous in nature the gas should be aboveatmospheric pressure. The preferred pressure range is about 1.05atmospheres to 10 atmospheres. It should be noted however that the upperlimit of pressure is determined by the pressure limitation of thecontainer in which the composition is contained and is not related tothe ingredients in the composition. Thus gases such as nitrogen, argon,helium, air or any mixtures thereof or any other gas preferably of aninert nature, or mixtures of gas will suffice. A suitable container maybe of the type described in copending application Ser. No. 74,434 filedSept. 22, 1970 entitled lncendiary Torch by Horace H. Helms, Jr.,Al-

exander i. Roznei' and Dana E. Spencer. When a con- 7 tainer such asdisclosed in the copending application is used the material is sealedinto said container so that the gas pressure is maintained. When readyfor use the material within the container, which in this case is atorch, is ignited and the alloying and oxidizing reaction is initiated.When the pressure inside the container exceeds the strength of thediaphragm the diaphragm ruptures and the expanding gases force themolten material through the nozzle.

Alternatively one may, instead of directly adding a gas to the torch,add a material to the instant composition which will decompose into gasor vaporize into gas when exposed to the heat produced by the alloyingand oxidizing reaction after ignition of the torch. One may add to theinstant composition solid materials such as powderedpolytetrafluoroethylene or other solid materials which will decomposeand/or vaporize to form gas or one may add liquid materials which willvaporize and/or decompose to form gas when exposed to the heat of thealloying and oxidizing reaction. It should be noted that the actualnature of the gas used is not believed to be important since the mainfunction of the gas is merely to expand with the increased temperatureresulting from the alloying and oxidizing reaction thus creating apressure which will force the molten pyrotechnic material out of thecontainer in which the composition is present. However, certain sourcesof gas such as powdered polytetrafluroethylene are preferred because oftheir availability, ease of handling, efficiency and price.

The source of gas constitutes not more than 20 weight percent of thecomposition. When the source of gas contains a solid, liquid or mixturethereof it is preferred to have the solid, liquid or mixture thereofpres ent to constitute l20 weight percent of the composition with l5weight percent being most preferred. Polytetrafluoroethylene is onepreferred source of gas since it can be mixed in powder form with theother constituents of the instant invention and when compacted itimparts mechanical strength to the pellets made therefrom.

The general nature of the invention having been set forth, the followingexamples are presented as specific illustrations thereof. It will beunderstood that the invention is not limited to these specific examples,but is susceptible to various modifications that will be recog nized byone of ordinary skill in the art.

Typical compositions of this invention are as follows: (Percentagesgiven by weight) EXAMPLE 1 Aluminum 23.95% Copper 18.80% Fe o 47.25%Polytetrafluoroethylene 10.00%

EXAMPLE ll Aluminum 21.65% Molybdenum 25.65% F8203 42.70% Polytetrafluoroethylene 10.00%

EXAMPLE lll Aluminum 28.45% or iron 29.45% Fe O 42.10%

The compositions of this invention may be mixed and compacted intodesired pellet shapes by using standard powder metallurgy techniques.Ignition of these compositions is accomplished by using any of thestandard pyrotechnic ignition techniques.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. A pyrotechnic composite comprising (1 a mixture of powders of (a)aluminum, (b) a metal oxide selected from the group consisting of Fe O Fe 0 CuO, Cr O C0 0 and mixtures thereof, and (c) a metal selected fromthe group consisting of iron, copper, silver, niobium, tungstenmolybdenum and mixtures thereof and (2) a source of gas selected fromthe group consisting of (a) gas maintained under a pressure of 1.05-l0atmospheres in a container, said gas expanding and forcing its way fromthe container when exposed to the heat of the alloying and oxidizingreaction, and (b) a fluorocarbon which is selected from the groupconsisting of (A) one solid substance, (B) a mixture of solidsubstances, (C) one liquid substance, (D) a mixture of liquid substancesand (E) mixtures thereof provided that any substance that is to be asource of gas must either vaporize to form gas when exposed to the heatof the alloying and oxidizing reaction, decompose to form gas whenexposed to the heat of the alloying and oxidizing reaction or form gasby both vaporizing and decomposing when exposed to the heat of thealloying and oxidizing reaction.

2. The composition of claim 1 wherein aluminum constitutes 5-35 weightpercent, metal oxide constitutes 2O8O weight percent, the metalconstitutes l-50 weight percent and the source of gas constitutes notmore than 20 weight percent of the composition.

3. The composition of claim 2 wherein the source of the gas comprises agas maintained under a pressure of 1.05-1O atmospheres in a container,said gas expanding and forcing its way from the container when exposedto the heat of the alloying and oxidizing reaction.

4. The composition of claim 3 wherein the source of gas is selected fromthe group consisting of air, nitrogen, inert gases and mixtures thereof.

5. The composition of claim 1 wherein the source of gas comprises afluorocarbon selected from the group consisting of (a) one solidsubstance, (b) a mixture of solid substances, (c) one liquid substance,((1) a mixture of liquid substances and (e) mixtures thereof providedthat any substance that is to be a source of gas must either vaporize toform gas when exposed to the heat of the alloying and oxidizingreaction, decompose to form gas when exposed to the heat of the alloyingand oxidizing reaction or form gas by both vaporizing and decomposingwhen exposed to the heat of the alloying and oxidizing reaction.

6. The composition of claim 2 wherein said source of gas constitutes1-20 weight percent of the composition comprising a fluorocarbonselected from the group consisting of (a) one solid substance, (b) amixture of solid substances, (c) one liquid substance, ((1) a mixture ofliquid substances and (e) mixtures thereof provided that any substancethat is to be a source of gas must vaporize to form gas when exposed tothe heat of the alloying and oxidizing reaction, decompose to form gaswhen exposed to the heat of the alloying and oxidizing reaction or formgas by both vaporizing and decomposing when exposed to the heat of thealloying and oxidizing reaction.

7. The composition of claim 5 wherein the fluorocarbon ispolytetrafluoroethylene.

8. The composition of claim 6 wherein the fluorocarbon ispolytetrafluoroethylene.

9. A pyrotechnic composition comprising a mixture of powders of (1)aluminum, (2) a metal oxide selected from the group consisting of Fe OFe O CuO, Cr O C0 0 and mixtures thereof, and (3) molybdenum.

. (5/69) UNITED STATES PATENT GFFICE QETIFICATE o c Patent 3 890 174Dated 1 7 June 1975 Inventor(s) Horace H Helms Jr and Alexander G RoznerIt is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

9 Correct inventor name from "Alexander G Rosner" t0 Alexander G. Rozner$igned and if salad this 0 ninth ay 0? September 1975 [SEAL] Arrest:

Q RUTH C. MASON C. MARSHALL DANN Arresting Officer (mnmissimu'r u/Parems and Trademarks

1. A PYROTECHNIC COMPOSITION COMPRISING (1) A MIXTURE OF POWDERS OF (A)ALUMINUM, (B) A METAL OXIDE SELECTED FROM THE GROUP CONSISTING OF FE2O3,FE3O4, CUO, CR2O3, CO3O4, AND MIXTURES THEREOF, AND (C) A METAL SELECTEDFROM THE GROUP CONSISTING OF IRON, COPPER, SILVER, NIOBIUM, TUNGSTEMMOLYBDENUM AND MIXTURES THEREOF AND (2) A SOURCE OF GAS SELECTED FROMTHE GROUP CONSISTING OF (A) GAS MAINTAINED UNDER A PRESSURE OF 1.05-10ATMOSPHERES IN A CONTAINER, SAID GAS EXPANDING AND FORCING ITS WAY FROMTHE CONTAINER, WHEN EXPOSED TO THE HEAT OF THEALLOYING AND OXIDIZINGREACTION, AND (B) A FLUOROCARBON WHICH IS SELECTED FROM THE GROUPCONSISTING OF (A) ONE SOLID SUBSTANCE, (B) A MIXTURE OF SOLIDSUBSTANCES, (C) ONE LIQUID SUBSTANCE, (D) A MIXTURE OF LIQUID SUBSTANCESAND (E) MIXTURES THEREOF PROVIDED THATANY SUBSTANCE THAT IS TO BE ASOURCE OF GAS MUST EITHER VAPORIZE TO FORM GAS WHEN EXPOSED TO THE HEATOF THE ALLOYING AND OXIDIZING REACTION, DECOMPOSE TO FORM GAS WHENEXPOSED TO THE HEAT OF THE ALLOYING AND OXIDIZING REACTION OR FORM GASBY BOTH VAPORIZING AND DECOMPOSING WHEN EXPOSED TO THE HEAT OF THEALLOYING AND OXIDIZING REACTION.
 2. The composition of claim 1 whereinaluminum constitutes 5-35 weight percent, metal oxide constitutes 20-80weight percent, the metal constitutes 1-50 weight percent and the sourceof gas constitutes not more than 20 weight percent of the composition.3. The composition of claim 2 wherein the source of the gas comprises agas maintained under a pressure of 1.05-10 atmospheres in a container,said gas expanding and forcing its way from the container when exposedto the heat of the alloying and oxidizing reaction.
 4. The compositionof claim 3 wherein the source of gas is selected from the groupconsisting of air, nitrogen, inert gases and mixtures thereof.
 5. Thecomposition of claim 1 wherein the source of gas comprises afluorocarbon selected from the group consisting of (a) one solidsubstance, (b) a mixture of solid substances, (c) one liquid substance,(d) a mixture of liquid substances and (e) mixtures thereof providedthat any substance that is to be a source of gas must either vaporize toform gas when exposed to the heat of the alloying and oxidizingreaction, decompose to form gas when exposed to the heat of the alloyingand oxidizing reaction or form gas by both vaporizing and decomposingwhen exposed to the heat of the alloying and oxidizing reaction.
 6. Thecomposition of claim 2 wherein said source of gas constitutes 1-20weight percent of the composition comprising a fluorocarbon selectedfrom the group consisting of (a) one solid substance, (b) a mixture ofsolid substances, (c) one liquid substance, (d) a mixture of liquidsubstances and (e) mixtures thereof provided that any substance that isto be a source of gas must vaporize to form gas when exposed to the heatof the alloying and oxidizing reaction, decompose to form gas whenexposed to the heat of the alloying and oxidizing reaction or form gasby both vaporizing and decomposing when exposed to the heat of thealloying and oxidizing reaction.
 7. The composition of claim 5 whereinthe fluorocarbon is polytetrafluoroethylene.
 8. The composition of claim6 wherein the fluorocarbon is polytetrafluoroethylene.
 9. A pyrotechniccomposition comprising a mixture of powders of (1) aluminum, (2) a metaloxide selected from the group consisting of Fe2O3, Fe3O4, CuO, Cr2O3,Co3O4, and mixtures thereof, and (3) molybdenum.
 9. A PYROTECHNICCOMPOSITION COMPRISING A MIXTURE OF POWDERS OF (1) ALUMINUM, (2) A METALOXIDE SELECTED FROM THE GROUP CONSISTING OF FE2O3, FE3O4, CUO, CR2O3,CO3O4, AND MIXTURES THEREOF, AND (3) MOLYBDENUM.